diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index 377acb2..dc36cd1 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -4527,7 +4527,8 @@
 	} else
 		rightmost_el = path_leaf_el(path);
 
-	credits += path->p_tree_depth + ocfs2_extend_meta_needed(di);
+	credits += path->p_tree_depth +
+		   ocfs2_extend_meta_needed(&di->id2.i_list);
 	ret = ocfs2_extend_trans(handle, credits);
 	if (ret) {
 		mlog_errno(ret);
diff --git a/fs/ocfs2/alloc.h b/fs/ocfs2/alloc.h
index 5c0f764..a0e334f 100644
--- a/fs/ocfs2/alloc.h
+++ b/fs/ocfs2/alloc.h
@@ -48,8 +48,14 @@
 int ocfs2_num_free_extents(struct ocfs2_super *osb,
 			   struct inode *inode,
 			   struct buffer_head *bh);
-/* how many new metadata chunks would an allocation need at maximum? */
-static inline int ocfs2_extend_meta_needed(struct ocfs2_dinode *fe)
+/*
+ * how many new metadata chunks would an allocation need at maximum?
+ *
+ * Please note that the caller must make sure that root_el is the root
+ * of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
+ * the result may be wrong.
+ */
+static inline int ocfs2_extend_meta_needed(struct ocfs2_extent_list *root_el)
 {
 	/*
 	 * Rather than do all the work of determining how much we need
@@ -59,7 +65,7 @@
 	 * new tree_depth==0 extent_block, and one block at the new
 	 * top-of-the tree.
 	 */
-	return le16_to_cpu(fe->id2.i_list.l_tree_depth) + 2;
+	return le16_to_cpu(root_el->l_tree_depth) + 2;
 }
 
 void ocfs2_dinode_new_extent_list(struct inode *inode, struct ocfs2_dinode *di);
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index e2008dc..bbe3f8b 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -1720,7 +1720,8 @@
 			goto out;
 		}
 
-		credits = ocfs2_calc_extend_credits(inode->i_sb, di,
+		credits = ocfs2_calc_extend_credits(inode->i_sb,
+						    &di->id2.i_list,
 						    clusters_to_alloc);
 
 	}
diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
index fda09c3..126aa21 100644
--- a/fs/ocfs2/dir.c
+++ b/fs/ocfs2/dir.c
@@ -1430,6 +1430,7 @@
 	int credits, num_free_extents, drop_alloc_sem = 0;
 	loff_t dir_i_size;
 	struct ocfs2_dinode *fe = (struct ocfs2_dinode *) parent_fe_bh->b_data;
+	struct ocfs2_extent_list *el = &fe->id2.i_list;
 	struct ocfs2_alloc_context *data_ac = NULL;
 	struct ocfs2_alloc_context *meta_ac = NULL;
 	handle_t *handle = NULL;
@@ -1488,7 +1489,7 @@
 		}
 
 		if (!num_free_extents) {
-			status = ocfs2_reserve_new_metadata(osb, fe, &meta_ac);
+			status = ocfs2_reserve_new_metadata(osb, el, &meta_ac);
 			if (status < 0) {
 				if (status != -ENOSPC)
 					mlog_errno(status);
@@ -1503,7 +1504,7 @@
 			goto bail;
 		}
 
-		credits = ocfs2_calc_extend_credits(sb, fe, 1);
+		credits = ocfs2_calc_extend_credits(sb, el, 1);
 	} else {
 		spin_unlock(&OCFS2_I(dir)->ip_lock);
 		credits = OCFS2_SIMPLE_DIR_EXTEND_CREDITS;
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index b6c483d..a31bba6 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -540,7 +540,7 @@
 		goto leave;
 	} else if ((!free_extents)
 		   && (ocfs2_alloc_context_bits_left(meta_ac)
-		       < ocfs2_extend_meta_needed(fe))) {
+		       < ocfs2_extend_meta_needed(&fe->id2.i_list))) {
 		mlog(0, "filesystem is really fragmented...\n");
 		status = -EAGAIN;
 		reason = RESTART_META;
@@ -652,7 +652,7 @@
 	 */
 	if (!num_free_extents ||
 	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
-		ret = ocfs2_reserve_new_metadata(osb, di, meta_ac);
+		ret = ocfs2_reserve_new_metadata(osb, &di->id2.i_list, meta_ac);
 		if (ret < 0) {
 			if (ret != -ENOSPC)
 				mlog_errno(ret);
@@ -732,7 +732,8 @@
 		goto leave;
 	}
 
-	credits = ocfs2_calc_extend_credits(osb->sb, fe, clusters_to_add);
+	credits = ocfs2_calc_extend_credits(osb->sb, &fe->id2.i_list,
+					    clusters_to_add);
 	handle = ocfs2_start_trans(osb, credits);
 	if (IS_ERR(handle)) {
 		status = PTR_ERR(handle);
@@ -790,7 +791,7 @@
 			mlog(0, "restarting transaction.\n");
 			/* TODO: This can be more intelligent. */
 			credits = ocfs2_calc_extend_credits(osb->sb,
-							    fe,
+							    &fe->id2.i_list,
 							    clusters_to_add);
 			status = ocfs2_extend_trans(handle, credits);
 			if (status < 0) {
diff --git a/fs/ocfs2/journal.h b/fs/ocfs2/journal.h
index 2178ebf..9485f80 100644
--- a/fs/ocfs2/journal.h
+++ b/fs/ocfs2/journal.h
@@ -340,11 +340,16 @@
 #define OCFS2_RENAME_CREDITS (3 * OCFS2_INODE_UPDATE_CREDITS + 3              \
 			     + OCFS2_UNLINK_CREDITS)
 
+/*
+ * Please note that the caller must make sure that root_el is the root
+ * of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
+ * the result may be wrong.
+ */
 static inline int ocfs2_calc_extend_credits(struct super_block *sb,
-					    struct ocfs2_dinode *fe,
+					    struct ocfs2_extent_list *root_el,
 					    u32 bits_wanted)
 {
-	int bitmap_blocks, sysfile_bitmap_blocks, dinode_blocks;
+	int bitmap_blocks, sysfile_bitmap_blocks, extent_blocks;
 
 	/* bitmap dinode, group desc. + relinked group. */
 	bitmap_blocks = OCFS2_SUBALLOC_ALLOC;
@@ -355,16 +360,16 @@
 	 * however many metadata chunks needed * a remaining suballoc
 	 * alloc. */
 	sysfile_bitmap_blocks = 1 +
-		(OCFS2_SUBALLOC_ALLOC - 1) * ocfs2_extend_meta_needed(fe);
+		(OCFS2_SUBALLOC_ALLOC - 1) * ocfs2_extend_meta_needed(root_el);
 
 	/* this does not include *new* metadata blocks, which are
-	 * accounted for in sysfile_bitmap_blocks. fe +
+	 * accounted for in sysfile_bitmap_blocks. root_el +
 	 * prev. last_eb_blk + blocks along edge of tree.
 	 * calc_symlink_credits passes because we just need 1
 	 * credit for the dinode there. */
-	dinode_blocks = 1 + 1 + le16_to_cpu(fe->id2.i_list.l_tree_depth);
+	extent_blocks = 1 + 1 + le16_to_cpu(root_el->l_tree_depth);
 
-	return bitmap_blocks + sysfile_bitmap_blocks + dinode_blocks;
+	return bitmap_blocks + sysfile_bitmap_blocks + extent_blocks;
 }
 
 static inline int ocfs2_calc_symlink_credits(struct super_block *sb)
diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index de7b93d..2a817bc 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -494,7 +494,7 @@
 }
 
 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
-			       struct ocfs2_dinode *fe,
+			       struct ocfs2_extent_list *root_el,
 			       struct ocfs2_alloc_context **ac)
 {
 	int status;
@@ -507,7 +507,7 @@
 		goto bail;
 	}
 
-	(*ac)->ac_bits_wanted = ocfs2_extend_meta_needed(fe);
+	(*ac)->ac_bits_wanted = ocfs2_extend_meta_needed(root_el);
 	(*ac)->ac_which = OCFS2_AC_USE_META;
 	slot = osb->slot_num;
 	(*ac)->ac_group_search = ocfs2_block_group_search;
diff --git a/fs/ocfs2/suballoc.h b/fs/ocfs2/suballoc.h
index 40d51da..3f96c87 100644
--- a/fs/ocfs2/suballoc.h
+++ b/fs/ocfs2/suballoc.h
@@ -59,8 +59,13 @@
 	return ac->ac_bits_wanted - ac->ac_bits_given;
 }
 
+/*
+ * Please note that the caller must make sure that root_el is the root
+ * of extent tree. So for an inode, it should be &fe->id2.i_list. Otherwise
+ * the result may be wrong.
+ */
 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
-			       struct ocfs2_dinode *fe,
+			       struct ocfs2_extent_list *root_el,
 			       struct ocfs2_alloc_context **ac);
 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
 			    struct ocfs2_alloc_context **ac);